import CryptoJS from "crypto-js";

const keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv" + "wxyz0123456789+/" + "=";
/* 字符串转base64 */

export const stringToBase64 = (input: string) => {
	input = escape(input);
	let output = "";
	let chr1: any = "";
	let chr2: any = "";
	let chr3: any = "";
	let enc1: any = "";
	let enc2: any = "";
	let enc3: any = "";
	let enc4: any = "";

	let i = 0;
	do {
		chr1 = input.charCodeAt(i++);
		chr2 = input.charCodeAt(i++);
		chr3 = input.charCodeAt(i++);
		enc1 = chr1 >> 2;
		enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
		enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
		enc4 = chr3 & 63;
		if (isNaN(chr2)) {
			enc3 = enc4 = 64;
		} else if (isNaN(chr3)) {
			enc4 = 64;
		}
		output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4);
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";
	} while (i < input.length);
	return output;
};

/* base64转字符串 */

export const base64ToString = (input: string) => {
	let output = "";
	let chr1: any = "";
	let chr2: any = "";
	let chr3: any = "";
	let enc1: any = "";
	let enc2: any = "";
	let enc3: any = "";
	let enc4: any = "";
	let i = 0;
	let base64test = /[^A-Za-z0-9\+\/\=]/g;
	if (base64test.exec(input)) {
		alert(
			"There were invalid base64 characters in the input text.\n" +
				"Valid base64 characters are A-Z, a-z, 0-9, '+', '/', and '='\n" +
				"Expect errors in decoding."
		);
	}
	input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
	do {
		enc1 = keyStr.indexOf(input.charAt(i++));
		enc2 = keyStr.indexOf(input.charAt(i++));
		enc3 = keyStr.indexOf(input.charAt(i++));
		enc4 = keyStr.indexOf(input.charAt(i++)) + "";
		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;
		output = output + String.fromCharCode(chr1);
		if (enc3 != 64) {
			output = output + String.fromCharCode(chr2);
		}
		if (+enc4 != 64) {
			output = output + String.fromCharCode(+chr3);
		}
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";
	} while (i < input.length);
	return unescape(output);
};

export const encodeBase64 = (str: string) => {
	const s = CryptoJS.enc.Utf8.parse(str);
	let reg = new RegExp("=", "g");
	return CryptoJS.enc.Base64.stringify(s)?.replace(reg, "");
};

export const decodeBase64 = (str: string) => {
	const s = CryptoJS.enc.Base64.parse(str);
	return s.toString(CryptoJS.enc.Utf8); // 需要引入 CryptoJS
};
